A stamp using a porous marking block with a large number of interconnected pores is widely used because it is capable of performing a marking operation without applying ink to a marking surface of the marking block in each marking operation.
Heretofore, this type of stamp has been configured such that ink stored in the ink storage body naturally flows down (permeates) into a porous marking block to permeatingly supply ink to a marking surface of the marking block, wherein ink replenishment for the stamp is performed by manually dropping liquid ink onto the marking surface or the ink storage body. During dropping of liquid ink, it is difficult for a user to accurately recognize an appropriate amount of liquid ink to be replenished, because a time required for ink permeation in the marking surface (state recovery in the marking surface) varies with position. Thus, the user is apt to replenish an excessive amount of liquid ink.
With a view to solving this problem, there has been proposed a stamp in which an ink cartridge containing ink is disposed on a back side of an ink-impregnated body, in such a manner that an ink supply port of the ink cartridge is in contact with the ink-impregnated body, as disclosed in the following Patent Document 1.
There has also been proposed a stamp in which an ink cartridge containing ink is disposed on a back side of a porous-rubber character block, in such a manner that an ink supply tube of the ink cartridge is inserted into the character block, as disclosed in the following Patent Document 2.